DataTable 树形构造加全部

            DataTable dtGx = new DataTable();
            dtGx = SqlHelper.SqlGetDataTable(StrSql, "tbUserGx");
            this.treeListGx.DataSource = dtGx;
            DataRow drGx = dtGx.NewRow();
            drGx["PID"] = ;
            drGx["FID"] = -;
            drGx["MID"] = DBNull.Value;
            drGx["Name"] = "全部";
            drGx["CompID"] = DBNull.Value;
            dtGx.Rows.Add(drGx);